Process of making articles of hard-rubber dust



May 13 [1924. 1,493,511

c. E. WING PROCESS OF MAKING ARTICLES 0F HARD RUBBER DUST Filed Oct. 6. 192 s IN VEN TOR.

-d% J TTORNEY.

Patented May 13, 1924.

UNITED :STATES -PATENT OFFICE CLAUDE E. WING, OF FLUSH ING, NEW YORK, ASSIGNOR TO AMERICAN HAIRD RUBBER CO., OF NEW YORK, N, Y., A CORPORATION OF NEW YORK.

PROCESS OF MAKING ARTICLES OF HARD-RUBBER DUST.

Application filed October 6, 1923. Serial No. 666,897.

- which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to use the same.

This invention relates to the manufacture of hard rubber articles out of hard rubber dust and to a process of re-inforcing said articles; the invention further relates to a process of graining or coloring the surfaces of said articles, the object of the invention being to improve the strength and appearance of articles made out of hard rubber ust.

To the accomplishment of the above objects and-to such others as may hereinafter appear, the invention comprises the use of re-inforcing sheets of vulcanized rubber, made from gum rubber and vulcanized, which can be inserted in the mold to cover the hard rubber dust, the whole being pressed andvulcanized' in the'mold to produce the finished article, the re-inforcing sheets of vulcanized rubber being grained or colored previous to being placedin the mold when it is desired to improve the appearance of the article.

Hard rubber dust is ordinarily obtained by grinding up hard rubber scrap, and is particularly applicable for use in'irregular shaped molds where accurate size and shape is required together with rapid vulcanization as hard rubber dust vulcanizes much faster and can be removed from the mold much quicker than new unvulcanized rub-' 0 set, after whlch the mold 1s cooled and taken her compound.

Articles made of hard rubber dust, while more easily vulcanized and removed from the mold in much less time, are not as strong a as articles made from new unvulcanized rubber compound, nor are they capable of being grained to resemble wood for example by using different colored dusts.

In order to overcome this difliculty reinforcing sheets of vulcanized rubber of various uniform colors or of variegated colors are out to, fit one or more sidesof the mold in which the hard rubber dust is inserted to the re uired amount after which the same is heate and the mold compressed, after which the mold is cooled moved.

and the article re- The provision of the re-inforcing sheets i of vulcanized rubber acts to materially strengthen the finished article andwin addition lends itself to coloring or graining not possible by the use of hard rubber dust alone.

In the drawings Figure 1 is a sectional view of a mold in open position showing the position of the hard rubber dust and a renforcing sheet of vulcanized rubber covering the same.

Figure-2 is a'view similar to Fig. 1 shoW- the mold in closed osition. igure 3 is a view 0 a thin iece-of vulcanized rubber compound used 1n the mold. Figure 4 is a view of a telephone ear cap made in accordance with the invention.

Referring to the drawings, 1 designates the body of the mold, 2 the upper die, and 3 the lower die, which are arranged to be heated, forced together, and cooled, such means not bein shown as they are of ordinary constructlon and well known. The

upper and lower dies 2 and 3 are cut in the present instance to form telephone ear I ca 5 as shown in Fig. 4. n

n the present instance and in accordance with the present invention, hard rubber dust 4, to the required amount, is inserted to cover the lower die 3, and a reinforcing piece ofvulcanized hard rubber 5 approximately one thirty second of an inch to one sixteenth of an inch thick, is placed over the top of the dust 4, the re-inforcin pieceof hard rubber 5 being preferably ess in diameter than the size ofthe'mold. The moldis heated and the up er die 2 forced into position as shown in ig. '2 and allowed to apart to remove the finished article or telecap with which it is vulcanized, making the, same less likely to break through hard usage.

The re-inforcing piece of vulcanized hard rubber can be made of different colored hard rubber compounds as taste may dietate, either to give a color different from ,the color of. the dust used or to give the appearanoe of grained wood. a

It is also to be noted that only one piece of hard rubber 5 is used to cover but one surface of the telephone ear ca 6, although if desired, another piece coul be used to cover a part of the bottom of the cap, if thought advisable to further strengthen or ornament the same.

While the invention has been described with particular reference to details, the same is not to beconsidered as limited thereto, as many changes can be made and still fall within the scope of the invention set forth in the following claims:

What I claim is 1. The process of strengthening hard rub- .ber articles made of hard rubber dust which comprises, facing one or more sides of a mold containing hard rubber dust with a reinforcing sheet of vulcanized hard rubber hard rubber dust which comprises, facing one or more sides of a mold containing hard rubber dust with a re-inforcing sheetof vulcanized hard rubber compound previously colored or rained and vulcanizing the same together y applying heat and pressure.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

CLAUDE E. WING. 

